Their limited battery range means that long-distance travel must be carefully planned, with charging stations along the route mapped out in advance. Wing it, and risk running out of juice in the middle of nowhere. And most charging stations aren’t all that fast, meaning long trips contain lots of downtime.

Now BMW, Volkswagen and a Bay Area electric vehicle charging company want to change that.

The two German automakers have teamed with ChargePoint of Campbell to install networks of high-speed chargers along two interstate corridors. One will link San Diego, Los Angeles, San Francisco and Portland. The other will stretch from Washington to Boston.

Both networks should be running by the end of the year. The three companies announced the project — which they will jointly fund — at the 2015 Washington Auto Show on Thursday.

The chargers will be quick — capable of restoring 80 percent of the charge in a BMW i3 or Volkswagen e-Golf in 30 minutes or less. They will be spaced no more than 50 miles apart, to ensure that drivers don’t get stranded.

The companies are following a path already blazed by Tesla Motors, which is building a nationwide network of its own high-speed supercharger stations along heavily traveled interstate highways, with 353 stations opened so far. But Tesla’s proprietary superchargers work only with the company’s Model S sedan, whose owners use the superchargers for free. They simply aren’t compatible with other electrics. Hence the need for another network.

“All car companies and charging companies came to the same conclusion a long time ago, that this is a critical piece for the adoption of electric cars,” said Pasquale Romano, ChargePoint’s CEO.

ChargePoint already operates 20,000 charging stations across North America, but the system so far includes just 110 DC fast chargers. The new charging corridors will add another 100. ChargePoint and its partners declined Thursday to say how much the project will cost, other than calling it “a very significant investment.”

Particularly on the West Coast, the corridors will connect cities that have emerged as electric vehicle hotspots. California alone accounts for roughly 40 percent of all electric cars sold nationwide, with more than 100,000 already on the road.

The stations within each corridor will contain several types of chargers, since not all electric cars can use the same recharging equipment.

Each station will include as many as two fast chargers. Some of those will operate at 50 kW, and will be capable of restoring 80 percent of the battery charge for an i3 or an e-Golf in as little as 20 minutes. Others will operate at 24 kW, taking about 10 minutes longer to recharge to the same level. All stations will also feature level 2 chargers, which are substantially slower but can be used by all electric cars, according to ChargePoint.

For the automakers, access to speedy charging between cities is essential to convincing drivers that electric vehicles aren’t just commuter cars.

“They’re buying more than a car — they’re buying a lifestyle,” said Stuart Gardner, product manager with Volkswagen of America. “This DC fast-charging network is one of the pieces to that holistic approach. It’s a key building block.”